multi-site/network setup

I just set up my WordPress primary domain to run multi-sites (network)… making changes to the wp-config.php and .htaccess files. Subdomains vs. subfolders not relevant, as setup in v 3.3 doesn’t ask to choose. Everything worked well until I tried to open the dashboard of my new (non-primary) site. There, I received a 404 (Page Not Found) error message. My host is GoDaddy and they have tried to help, but essentially gave up on me and told me I had to find the solution somewhere else. Anyone have a suggestion? Thank you!! Kathy